The Mystery of Hamlet: A Solution – why does Hamlet take up to four hours stage time and up to six months narrative duration to kill Claudius? Stagman suggests it’s the “single most famous and controversial issue in Literature”. I'm not so sure.
My prejudice against this line of literary criticism is that if you set aside the play’s literary merit and whatever secret codes Shakespeare (or "playful beguiler" as the cover has it) may have layered into the text and simply treat it as a piece of drama dealing with human emotion, there is no question. Hamlet, an aristocratic prince and scholar (and depending upon which text you're reading a teenager), has been tasked by the ghost of his father to murder his uncle, and though his immediate reaction might be to speak of revenge, a very human reaction, of course he dithers when faced with the reality of process. Instead he fains madness and does everything he can to get Claudius to expose himself and it’s only after, in a fit of oppressed anger, he kills Polonius, that he finds that he has that murderous ability within him.